1. Field of the Invention
This invention relates to a method and apparatus for producing an acoustical fiberboard, and more particularly is directed to the surface texturing of a mineral ceiling panel with a wheel blast machine.
2. Description of the Prior Art
Shaped products made from fibers and a binder, which are typically acoustical in nature, i.e., capable of attenuating sound, are well known in the art and are widely used today. Examples of such shaped products include ceiling panels and tiles, wall boards, screen dividers, construction panels, and the like. The conventional process for making these products involves use of a fourdrinier-type machine wherein an aqueous mixture comprising the fiber and binder is cast on a forming screen, and subsequently consolidated and dewatered. Normally, the formed board is passed to an oven for final drying.
A wide variety of processes have been employed in the past to produce a textured surface on these fiberboards, including cutting, routing, abrading, using adhesive inks or templates, etc. Frequently, it has been difficult to texture the boards without considerably weakening them or otherwise disadvantageously affecting them. A particular problem has been to carry out the texturing in such a way that a pleasing and uniform pattern is created on the board while the overall board properties are preserved. This problem is particularly exacerbated when the boards are extra wide and/or produced at high line speeds.